with brian williams. >>> good evening, he was a u.s. foreign service officer, a diplomat representing his country, all he ever wanted to be, he didn't ask for cushy assignments. be, chris steven was the u.s. ambassador to libya, killed last night in the attack in the city of benghazi. a total of four americans were killed, america -- the president vowed justice will be done. ill are justice, turns out turns out 911 was a bad day for overseas, protesters in cairo destroyed the american flag in cairo and egypt, and then in benghazi, where we begin tonight, we have our chief foreign correspondent, richard, good evening. >> reporter: good evening, brian, we hoped to broadcast in front of the u.s. embassy here in cairo, but had to leave as egyptian security forces clashed with the demonstrators there, pushing them back, using tear gas to try to stop assaults like the ones yesterday, which we are learning much more about. two attacks on u.s. buildings, one here in cairo, spontaneous, passion, harmless, the other in benghazi, focused and deadly. at 4:00, protesters in cairo answer a preacher's c